When personnel are located underground, such as in mines, tunnels or boreholes, a need exists to establish and maintain communications with such personnel. This is important in emergency situations such as collapsed tunnels or mines, accidents or other crises. A similar need is recognized in association with events and communications occurring in littoral waters. While telephone lines between fixed points provide some measure of communication, these fixed locations may be difficult or impossible to reach under such conditions. Furthermore, radio communications have been problematic and often unreliable in these environments. Alternative systems and methods for establishing and maintaining communications are desired.